/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.commons.pool2.impl;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertNull;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.time.Duration;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  import java.util.concurrent.TimeUnit;
  
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.Timeout;
  
  /**
   * Tests for {@link LinkedBlockingDeque}.
   */
  public class TestLinkedBlockingDeque {
  
      private static final Duration TIMEOUT_50_MILLIS = Duration.ofMillis(50);
      private static final Integer ONE = Integer.valueOf(1);
      private static final Integer TWO = Integer.valueOf(2);
      private static final Integer THREE = Integer.valueOf(3);
  
      LinkedBlockingDeque<Integer> deque;
  
      @BeforeEach
      public void setUp() {
          deque = new LinkedBlockingDeque<>(2);
      }
  
      @Test
      public void testAdd() {
          assertTrue(deque.add(ONE));
          assertTrue(deque.add(TWO));
          assertThrows(IllegalStateException.class, () -> deque.add(THREE));
          assertThrows(NullPointerException.class, () -> deque.add(null));
      }
  
      @Test
      public void testAddFirst() {
          deque.addFirst(ONE);
          deque.addFirst(TWO);
          assertEquals(2, deque.size());
          assertThrows(IllegalStateException.class, () -> deque.add(THREE));
          assertEquals(Integer.valueOf(2), deque.pop());
      }
  
      @Test
      public void testAddLast() {
          deque.addLast(ONE);
          deque.addLast(TWO);
          assertEquals(2, deque.size());
          assertThrows(IllegalStateException.class, () -> deque.add(THREE));
          assertEquals(Integer.valueOf(1), deque.pop());
      }
  
      @Test
      public void testClear() {
          deque.add(ONE);
          deque.add(TWO);
          deque.clear();
          deque.add(ONE);
          assertEquals(1, deque.size());
      }
  
      @Test
      public void testConstructors() {
          LinkedBlockingDeque<Integer> deque = new LinkedBlockingDeque<>();
          assertEquals(Integer.MAX_VALUE, deque.remainingCapacity());
  
          deque = new LinkedBlockingDeque<>(2);
          assertEquals(2, deque.remainingCapacity());
  
          deque = new LinkedBlockingDeque<>(Arrays.asList(ONE, TWO));
          assertEquals(2, deque.size());
  
         assertThrows(NullPointerException.class, () -> new LinkedBlockingDeque<>(Arrays.asList(ONE, null)));
     }
 
     @Test
     public void testContains() {
         deque.add(ONE);
         assertTrue(deque.contains(ONE));
         assertFalse(deque.contains(TWO));
         assertFalse(deque.contains(null));
         deque.add(TWO);
         assertTrue(deque.contains(TWO));
         assertFalse(deque.contains(THREE));
     }
 
     @Test
     public void testDescendingIterator() {
         assertThrows(NoSuchElementException.class, () -> deque.descendingIterator().next());
         deque.add(ONE);
         deque.add(TWO);
         final Iterator<Integer> iter = deque.descendingIterator();
         assertEquals(Integer.valueOf(2), iter.next());
         iter.remove();
         assertEquals(Integer.valueOf(1), iter.next());
     }
 
     @Test
     public void testDrainTo() {
         Collection<Integer> c = new ArrayList<>();
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(2, deque.drainTo(c));
         assertEquals(2, c.size());
 
         c = new ArrayList<>();
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(1, deque.drainTo(c, 1));
         assertEquals(1, deque.size());
         assertEquals(1, c.size());
         assertEquals(Integer.valueOf(1), c.iterator().next());
     }
 
     @Test
     public void testElement() {
         assertThrows(NoSuchElementException.class, () -> deque.element());
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(Integer.valueOf(1), deque.element());
     }
 
     @Test
     public void testGetFirst() {
         assertThrows(NoSuchElementException.class, () -> deque.getFirst());
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(Integer.valueOf(1), deque.getFirst());
     }
 
     @Test
     public void testGetLast() {
         assertThrows(NoSuchElementException.class, () -> deque.getLast());
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(Integer.valueOf(2), deque.getLast());
     }
 
     @Test
     public void testIterator() {
         assertThrows(NoSuchElementException.class, () -> deque.iterator().next());
         deque.add(ONE);
         deque.add(TWO);
         final Iterator<Integer> iter = deque.iterator();
         assertEquals(Integer.valueOf(1), iter.next());
         iter.remove();
         assertEquals(Integer.valueOf(2), iter.next());
     }
 
     @Test
     public void testOffer() {
         assertTrue(deque.offer(ONE));
         assertTrue(deque.offer(TWO));
         assertFalse(deque.offer(THREE));
         assertThrows(NullPointerException.class, () -> deque.offer(null));
     }
 
     @Test
     public void testOfferFirst() {
         deque.offerFirst(ONE);
         deque.offerFirst(TWO);
         assertEquals(2, deque.size());
         assertThrows(NullPointerException.class, () -> deque.offerFirst(null));
         assertEquals(Integer.valueOf(2), deque.pop());
     }
 
     @Test
     public void testOfferFirstWithTimeout() throws InterruptedException {
         assertThrows(NullPointerException.class, () -> deque.offerFirst(null, TIMEOUT_50_MILLIS));
         assertTrue(deque.offerFirst(ONE, TIMEOUT_50_MILLIS));
         assertTrue(deque.offerFirst(TWO, TIMEOUT_50_MILLIS));
         assertFalse(deque.offerFirst(THREE, TIMEOUT_50_MILLIS));
     }
 
     @Test
     public void testOfferLast() {
         deque.offerLast(ONE);
         deque.offerLast(TWO);
         assertEquals(2, deque.size());
         assertThrows(NullPointerException.class, () -> deque.offerLast(null));
         assertEquals(Integer.valueOf(1), deque.pop());
     }
 
     @Test
     public void testOfferLastWithTimeout() throws InterruptedException {
         assertThrows(NullPointerException.class, () -> deque.offerLast(null, TIMEOUT_50_MILLIS));
         assertTrue(deque.offerLast(ONE, TIMEOUT_50_MILLIS));
         assertTrue(deque.offerLast(TWO, TIMEOUT_50_MILLIS));
         assertFalse(deque.offerLast(THREE, TIMEOUT_50_MILLIS));
     }
 
     @Test
     public void testOfferWithTimeout() throws InterruptedException {
         assertTrue(deque.offer(ONE, TIMEOUT_50_MILLIS));
         assertTrue(deque.offer(TWO, TIMEOUT_50_MILLIS));
         assertFalse(deque.offer(THREE, TIMEOUT_50_MILLIS));
         assertThrows(NullPointerException.class, () -> deque.offer(null, TIMEOUT_50_MILLIS));
     }
 
     @Test
     public void testPeek() {
         assertNull(deque.peek());
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(Integer.valueOf(1), deque.peek());
     }
 
     @Test
     public void testPeekFirst() {
         assertNull(deque.peekFirst());
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(Integer.valueOf(1), deque.peekFirst());
     }
 
     @Test
     public void testPeekLast() {
         assertNull(deque.peekLast());
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(Integer.valueOf(2), deque.peekLast());
     }
 
     @Test
     public void testPollFirst() {
         assertNull(deque.pollFirst());
         assertTrue(deque.offerFirst(ONE));
         assertTrue(deque.offerFirst(TWO));
         assertEquals(Integer.valueOf(2), deque.pollFirst());
     }
 
     @Test
     public void testPollFirstWithTimeout() throws InterruptedException {
         assertNull(deque.pollFirst());
         assertNull(deque.pollFirst(TIMEOUT_50_MILLIS));
     }
 
     @Test
     public void testPollLast() {
         assertNull(deque.pollLast());
         assertTrue(deque.offerFirst(ONE));
         assertTrue(deque.offerFirst(TWO));
         assertEquals(Integer.valueOf(1), deque.pollLast());
     }
 
     @Test
     public void testPollLastWithTimeout() throws InterruptedException {
         assertNull(deque.pollLast());
         assertNull(deque.pollLast(TIMEOUT_50_MILLIS));
     }
 
     @Test
     public void testPollWithTimeout() throws InterruptedException {
         assertNull(deque.poll(TIMEOUT_50_MILLIS));
         assertNull(deque.poll(TIMEOUT_50_MILLIS));
     }
 
     @Test
     public void testPop() {
         assertThrows(NoSuchElementException.class, () -> deque.pop());
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(Integer.valueOf(1), deque.pop());
         assertThrows(NoSuchElementException.class, () -> {
             deque.pop();
             deque.pop();
         });
     }
 
     /*
      * https://issues.apache.org/jira/browse/POOL-281
      *
      * Should complete almost instantly when the issue is fixed.
      */
     @Test
     @Timeout(value = 10000, unit = TimeUnit.MILLISECONDS)
     public void testPossibleBug() {
 
         deque = new LinkedBlockingDeque<>();
         for (int i = 0; i < 3; i++) {
             deque.add(Integer.valueOf(i));
         }
 
         // This particular sequence of method calls() (there may be others)
         // creates an internal state that triggers an infinite loop in the
         // iterator.
         final Iterator<Integer> iter = deque.iterator();
         iter.next();
 
         deque.remove(Integer.valueOf(1));
         deque.remove(Integer.valueOf(0));
         deque.remove(Integer.valueOf(2));
 
         iter.next();
     }
 
     @Test
     public void testPush() {
         deque.push(ONE);
         deque.push(TWO);
         assertEquals(2, deque.size());
         assertThrows(IllegalStateException.class, () -> deque.push(THREE));
         assertEquals(Integer.valueOf(2), deque.pop());
     }
 
     @Test
     public void testPut() throws InterruptedException {
         assertThrows(NullPointerException.class, () -> deque.put(null));
         deque.put(ONE);
         deque.put(TWO);
     }
 
     @Test
     public void testPutFirst() throws InterruptedException {
         assertThrows(NullPointerException.class, () -> deque.putFirst(null));
         deque.putFirst(ONE);
         deque.putFirst(TWO);
         assertEquals(2, deque.size());
         assertEquals(Integer.valueOf(2), deque.pop());
     }
 
     @Test
     public void testPutLast() throws InterruptedException {
         assertThrows(NullPointerException.class, () -> deque.putLast(null));
         deque.putLast(ONE);
         deque.putLast(TWO);
         assertEquals(2, deque.size());
         assertEquals(Integer.valueOf(1), deque.pop());
     }
 
     @Test
     public void testRemove() {
         assertThrows(NoSuchElementException.class, deque::remove);
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(Integer.valueOf(1), deque.remove());
     }
 
     @Test
     public void testRemoveFirst() {
         assertThrows(NoSuchElementException.class, deque::removeFirst);
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(Integer.valueOf(1), deque.removeFirst());
         assertThrows(NoSuchElementException.class, () -> {
             deque.removeFirst();
             deque.removeFirst();
         });
     }
 
     @Test
     public void testRemoveLast() {
         assertThrows(NoSuchElementException.class, deque::removeLast);
         deque.add(ONE);
         deque.add(TWO);
         assertEquals(Integer.valueOf(2), deque.removeLast());
         assertThrows(NoSuchElementException.class, () -> {
             deque.removeLast();
             deque.removeLast();
         });
     }
 
     @Test
     public void testRemoveLastOccurrence() {
         assertFalse(deque.removeLastOccurrence(null));
         assertFalse(deque.removeLastOccurrence(ONE));
         deque.add(ONE);
         deque.add(ONE);
         assertTrue(deque.removeLastOccurrence(ONE));
         assertEquals(1, deque.size());
     }
 
     @Test
     public void testTake() throws InterruptedException {
         assertTrue(deque.offerFirst(ONE));
         assertTrue(deque.offerFirst(TWO));
         assertEquals(Integer.valueOf(2), deque.take());
     }
 
     @Test
     public void testTakeFirst() throws InterruptedException {
         assertTrue(deque.offerFirst(ONE));
         assertTrue(deque.offerFirst(TWO));
         assertEquals(Integer.valueOf(2), deque.takeFirst());
     }
 
     @Test
     public void testTakeLast() throws InterruptedException {
         assertTrue(deque.offerFirst(ONE));
         assertTrue(deque.offerFirst(TWO));
         assertEquals(Integer.valueOf(1), deque.takeLast());
     }
 
     @Test
     public void testToArray() {
         deque.add(ONE);
         deque.add(TWO);
         Object[] arr = deque.toArray();
         assertEquals(Integer.valueOf(1), arr[0]);
         assertEquals(Integer.valueOf(2), arr[1]);
 
         arr = deque.toArray(new Integer[0]);
         assertEquals(Integer.valueOf(1), arr[0]);
         assertEquals(Integer.valueOf(2), arr[1]);
 
         arr = deque.toArray(new Integer[0]);
         assertEquals(Integer.valueOf(1), arr[0]);
         assertEquals(Integer.valueOf(2), arr[1]);
     }
 }